Closing the phosphorous-efficiency gap

Oct 24, 2011
Soil core samples taken for analysis. Image credit - Carl Davies, CSIRO

Ways to reduce the costs of phosphorus fertiliser use on farms – critical for sustaining high agricultural production in many Australian farming systems – have been identified in a new suite of journal papers.

The price for phosphorus is increasing steadily and has doubled over the last 10 years.

Providing a national review of phosphorus use in grazing and cropping systems, Australian and international scientists found that Australia’s pasture systems, on average, have low phosphorus-use efficiency (15-30 per cent) while most broadacre grain operations average around 50-60 per cent efficiency.

They say that the major avenue for addressing inefficiencies and increases in phosphorus fertiliser cost could be addressed through improving fertiliser technologies; breeding plants that can more efficiently take up phosphorous from the soil or grow better in lower-phosphorus soils; and applying the right amounts of phosphorus fertilisers at the right times.

According to Dr Richard Simpson from CSIRO’s Sustainable Agriculture Flagship, with a few exceptions, improvements in using phosphorus efficiently have been stalled for years.

“Ideally we would like to be applying only one kilogram of phosphorus as fertiliser to produce one kilogram of phosphorus in food and fibre products,” Dr Simpson said.

“But for every kilogram of phosphorus that ends up in farm products, usually two to four kilograms of phosphorus has been added to the soil in fertiliser. This is because most Australian soils tend to hold on to phosphorus when they are fertilised and plants can’t access it.

“We really can’t afford to continue doing that. From a dollar point of view, improved efficiency will mean we can reduce costs for our farmers, but also, high-quality phosphorus reserves are a finite global resource – the more effectively we use phosphorus the better global citizens we will be,” Dr Simpson said.

“This latest work is showing us how we may be able to achieve improved efficiency through improved practices and technologies.”

Globally, phosphorus fertilisers are an important input for producing food. For most Australian farms, using phosphorus fertiliser (along with other inputs like nitrogen and water) ensures high production per hectare therefore helping to minimise overhead costs and support more efficient use of land and other resources. This helps Australian enterprises to maximise their returns on investment and maintain their global competitiveness.

“Unfortunately, the price of fertiliser has doubled over the last decade and some meat and wool producers are deciding to forego productivity gains as they need to reduce stocking rates,” Dr Simpson said.

“In addition, the cost of energy needed to source and produce fertilisers is rising, so further steady increases in fertiliser costs are expected.

“The key thing for farmers to think about is whether they are optimising fertiliser application for their production goals. Applying phosphorus amounts that exceed the targets for optimal management simply cost more in fertiliser for no gain.

“If the inefficiency gap can be closed there are big opportunities to maintain high farm productivity with reduced food production costs and reduced losses to the environment such as into waterways.

“While it’s not going to be easy, there are immediate steps we can take and there are many improvements possible. Pasture systems particularly provide the biggest opportunity,” he said.

CSIRO’s Sustainable Agriculture Flagship is working with industry and farmers to more efficiently use resources such as nutrients, water, and labour to benefit both productivity and the environment.

Explore further: US delays decision on Keystone pipeline project

More information: For online papers published in preparation for a special edition of the journal Plant and Soil see Volume 1 / 1948 - Volume 348 / 2011.

add to favorites email to friend print save as pdf

Related Stories

Recycled garden compost reduces phosphorus in soils

Jun 01, 2007

Broccoli, eggplant, cabbage and capsicum grown with compost made from recycled garden offcuts have produced equivalent yields to those cultivated by conventional farm practice, but without the subsequent build up of phosphorus.

Helping feed the world without polluting its waters

Feb 03, 2011

(PhysOrg.com) -- A growing global population has lead to increasing demands for food. Farmers around the world rely, at least in part on phosphorus-based fertilizers in order to sustain and improve crop yields. But the overuse ...

Calculating agriculture's phosphorus footprint

Apr 13, 2010

Balancing phosphorus levels in crop lands is a key factor that is often overlooked in discussions of global food security, according to a paper published in the International Journal of Agricultural Resources, Governance an ...

Unsung bedrock of prosperity

Apr 18, 2011

Modern agriculture would be inconceivable without phosphate fertilizers - and it needs more and more of them. Experts warn of an imminent phosphorus shortage. But not Roland Scholz from the Institute of Environmental ...

Urban impacts on phosphorus in streams

Aug 11, 2011

Although phosphorus is an essential nutrient for all life forms, essential amounts of the chemical element can cause water quality problems in rivers, lakes, and coastal zones. High concentrations of phosphorus in aquatic ...

Recommended for you

US delays decision on Keystone pipeline project

Apr 18, 2014

The United States announced Friday a fresh delay on a final decision regarding a controversial Canada to US oil pipeline, saying more time was needed to carry out a review.

New research on Earth's carbon budget

Apr 18, 2014

(Phys.org) —Results from a research project involving scientists from the Desert Research Institute have generated new findings surrounding some of the unknowns of changes in climate and the degree to which ...

User comments : 0

More news stories

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

UN weather agency warns of 'El Nino' this year

The UN weather agency Tuesday warned there was a good chance of an "El Nino" climate phenomenon in the Pacific Ocean this year, bringing droughts and heavy rainfall to the rest of the world.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...